I have a crown boiler that is about 16 years old. Just recently the pressure relief valve started leaking. I replaced bothe the pressure relief valve and the expansion tank and the pressure still bulds up over the 30psi. Any suggestions?
pressure relief valve leaks
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Could be a anything that affects temp or pressure.
If the water pressure creeps up to 30+ psi when the boiler is cold, then your water pressure reducing valve may just need to be adjusted but will usually need to be replaced.
If it only gets up there when the boiler is hot then make sure the piping connecting to the exp tank is not plugged. Some poor configurations can allow sediment to collect on that leg.
Poor pump circulation? A gate valve thats partially closed? An air lock in one of the rads?
What is you temp reading at the tridicator?
Submit pictures of your set up if you can't sort it out.
Yesterday I had a boiler doing that because the little electrical switch on a zone valve was stuck "on" allowing the boiler to fire up without a zone valve actually being open.
If the water pressure creeps up to 30+ psi when the boiler is cold, then your water pressure reducing valve may just need to be adjusted but will usually need to be replaced.
If it only gets up there when the boiler is hot then make sure the piping connecting to the exp tank is not plugged. Some poor configurations can allow sediment to collect on that leg.
Poor pump circulation? A gate valve thats partially closed? An air lock in one of the rads?
What is you temp reading at the tridicator?
Submit pictures of your set up if you can't sort it out.
Yesterday I had a boiler doing that because the little electrical switch on a zone valve was stuck "on" allowing the boiler to fire up without a zone valve actually being open.
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Sounds like a bad autofill valve to me...
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Fill valve.
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unusual residential boiler psi problem
OK...You have done the normal things for pressure control so if the new press reg was installed facing the right way? Then...
Does the boiler always show a high psi or does it fluxuate.
If it is 12- 25 psi and only goes up over 30+psi when it's running then...
Watch your boiler go from cool to hot. Tell us when the boiler pressure starts to climb in psi.
Normally in a common boiler the thermostat calls for heat/ the zone valve will open and trip an electrical connection if you have more than one heating zone/ if you have a damper motor on the vent it will also need to open which will trip another switch/ then the main gas will start firing/ the pump will come on right away or may wait for the aquastat temp controls depending on how it's wired/ hot water will start flowing out of the boiler furthest from the pump while cooler water will be returning to the pump/ you will feel this on the piping. The main gas will continue to fire until
the thermostat shuts it off although your aquastat may turn it on & off during the process to prevent the water from getting too hot. When the thermostat does shut off the main gas, the pump will usually shut down at the same time.
With this all in mind, tell us WHEN in this process does the pressure reading change and to what?
Do you have a slaved system that is also heating your domestic water through your boiler or is your Hot water tank independant.
OK...You have done the normal things for pressure control so if the new press reg was installed facing the right way? Then...
Does the boiler always show a high psi or does it fluxuate.
If it is 12- 25 psi and only goes up over 30+psi when it's running then...
Watch your boiler go from cool to hot. Tell us when the boiler pressure starts to climb in psi.
Normally in a common boiler the thermostat calls for heat/ the zone valve will open and trip an electrical connection if you have more than one heating zone/ if you have a damper motor on the vent it will also need to open which will trip another switch/ then the main gas will start firing/ the pump will come on right away or may wait for the aquastat temp controls depending on how it's wired/ hot water will start flowing out of the boiler furthest from the pump while cooler water will be returning to the pump/ you will feel this on the piping. The main gas will continue to fire until
the thermostat shuts it off although your aquastat may turn it on & off during the process to prevent the water from getting too hot. When the thermostat does shut off the main gas, the pump will usually shut down at the same time.
With this all in mind, tell us WHEN in this process does the pressure reading change and to what?
Do you have a slaved system that is also heating your domestic water through your boiler or is your Hot water tank independant.
I have an indirect domestic hot water heater. With the outside temp being 80+ lately the only zone that opens is the hot water heater. I can bleed the pressure off (down to about 15psi) and is climbs but very slowly. It does howerver, climb faster if the boiler is running. I have not tried to shut the boiler down to see if it still climbs.
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I had exactly the same problem, and I also had an indirect hot water heater. My indirect heater consisted of a coil of copper pipe inside the boiler, which circulated hot boiler water through a storage tank, where the domestic water was heated. In my case, there was a small leak in the coil inside the boiler. Since the pressure in the indirect coil is house pressure (50 psi in my case), and is not controlled by the boiler makeup water pressure regulator, the effect of a leak in the coil is to pressurize the water in the boiler to house pressure.
I could have replaced the coil, which would have cost about $700, and came with no guarantees, because my boiler is old (1959), and the bolts holding the coils to the boiler are rusty and suspect. I chose to purchase an electric hot water heater and dismantle the indirect system. I capped off the coil lines where they enter the boiler. Problem solved.
I could have replaced the coil, which would have cost about $700, and came with no guarantees, because my boiler is old (1959), and the bolts holding the coils to the boiler are rusty and suspect. I chose to purchase an electric hot water heater and dismantle the indirect system. I capped off the coil lines where they enter the boiler. Problem solved.
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I think modern indirect water heaters are "tank within a tank" design. Inner tank holds domestic drinking water, under pressure. Outer tank holds boiler water.
If there's a leak in the inner tank, the problem Daniel H. had could exist in your system.
If there's a leak in the inner tank, the problem Daniel H. had could exist in your system.
Isolating your heating boiler feed lines to your hotwater tank will tell you if the hot water tank is the problem. Turn the power off to the boiler /turn off the gate valves on the two lines going to your tank/ reduce the psi in the boiler to 20 psi and see if that pressure remains stable. If the boiler is cool and the psi doesn't creep back up you've got a bad tank coil.
If you don't have gate valves on both lines going to your hot water tank then..turn off the power to the boiler/ turn off the domestic cold water gate valve feed line to the hot water tank/ open a hot water tap in the house/ reduce the boiler psi to 20 and watch if it creeps back up.
I tried to post this a few times yesterday but it disapeared twice and I gave up.
Cheers
If you don't have gate valves on both lines going to your hot water tank then..turn off the power to the boiler/ turn off the domestic cold water gate valve feed line to the hot water tank/ open a hot water tap in the house/ reduce the boiler psi to 20 and watch if it creeps back up.
I tried to post this a few times yesterday but it disapeared twice and I gave up.
Cheers
I have tried just about everything I can think of and also what's been suggested and the pressure relief valve continues to leak. I have bled the pressure down to 20 psi and as long as the boiler doesn't run it stays constant. As soon as the boiler starts up the pressure begins to increase until it reaches 30 psi and then it drips. Once the boiler shuts off it will drop to about 28 psi and remain constant.
Any more ideas?
Any more ideas?
I came across this once - very frustrating. I eventually found out that the bottom port of the spirovent/air scoop where the expansion tank gets screwed-in was clogged with sediment - basically forming a dam such that the expansion tank was rendered useless. I think someone must've used copious amounts of boiler seal liquid to "fix" a leak somewhere in the system.
Drain the system, remove the expansion tank and check that threaded tapping. Make sure it isn't clogged with sediment, scale or "other" (e.g. - coagulated boiler seal).
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